Causal association between skin cancer and immune cells: mendelian randomization (MR) study.

BACKGROUND: Numerous meta-analyses and clinical studies have shown that subtypes of immune cells are associated with the development of skin cancer, but it is not clear whether this association is causal or biased. Mendelian randomization (MR) analysis reduces the effect of confounding factors and improves the accuracy of the results when compared to traditional studies. Thus, in order to examine the causal relationship between various immune cell and skin cancer, this study employs two-sample MR. METHODS: This study assesses the causal association between 731 immune cell characteristics and skin cancer using a two-sample Mendel randomization (MR) methodology. Multiple MR methods were used to bias and to derive reliable estimates of causality between instrumental variables and outcomes. Comprehensive sensitivity analyses were used to validate the stability, heterogeneity and horizontal multiplicity of the results. RESULTS: We discovered that potential causal relationships between different types of immune cells and skin cancer disease. Specifically, one type of immune cell as potentially causal to malignant melanoma of skin (MM), eight different types of immune cells as potentially causal to basal cell carcinoma (BCC), four different types of immune cells as potentially causal to actinic keratosis (AK), and no different types of immune cells were found to have a potential causal association with squamous cell carcinoma(SCC), with stability in all of the results. CONCLUSION: This study demonstrates the close connection between immune cells and skin cancer disease by genetic means, which enriches the current knowledge about the role of immune cells in skin cancer and also contributes to the design of therapeutic strategies from an immunological perspective.

Advancing immunotherapy for melanoma: the critical role of single-cell analysis in identifying predictive biomarkers.

Melanoma, a malignant skin cancer arising from melanocytes, exhibits rapid metastasis and a high mortality rate, especially in advanced stages. Current treatment modalities, including surgery, radiation, and immunotherapy, offer limited success, with immunotherapy using immune checkpoint inhibitors (ICIs) being the most promising. However, the high mortality rate underscores the urgent need for robust, non-invasive biomarkers to predict patient response to adjuvant therapies. The immune microenvironment of melanoma comprises various immune cells, which influence tumor growth and immune response. Melanoma cells employ multiple mechanisms for immune escape, including defects in immune recognition and epithelial-mesenchymal transition (EMT), which collectively impact treatment efficacy. Single-cell analysis technologies, such as single-cell RNA sequencing (scRNA-seq), have revolutionized the understanding of tumor heterogeneity and immune microenvironment dynamics. These technologies facilitate the identification of rare cell populations, co-expression patterns, and regulatory networks, offering deep insights into tumor progression, immune response, and therapy resistance. In the realm of biomarker discovery for melanoma, single-cell analysis has demonstrated significant potential. It aids in uncovering cellular composition, gene profiles, and novel markers, thus advancing diagnosis, treatment, and prognosis. Additionally, tumor-associated antibodies and specific genetic and cellular markers identified through single-cell analysis hold promise as predictive biomarkers. Despite these advancements, challenges such as RNA-protein expression discrepancies and tumor heterogeneity persist, necessitating further research. Nonetheless, single-cell analysis remains a powerful tool in elucidating the mechanisms underlying therapy response and resistance, ultimately contributing to the development of personalized melanoma therapies and improved patient outcomes.

Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.

While Merkel cell polyomavirus (MCPyV or MCV) is an abundant virus frequently shed from healthy skin, it is one of the most lethal tumor viruses in immunocompromised individuals, highlighting the crucial role of host immunity in controlling MCPyV oncogenic potential. Despite its prevalence, very little is known about how MCPyV interfaces with the host immune response to maintain asymptomatic persistent infection and how inadequate control of MCPyV infection triggers MCC tumorigenesis. In this study, we discovered that the MCPyV protein, known as the Alternative Large Tumor Open Reading Frame (ALTO), also referred to as middle T, effectively primes and activates the STING signaling pathway. It recruits Src kinase into the complex of STING downstream kinase TBK1 to trigger its autophosphorylation, which ultimately activates the subsequent antiviral immune response. Combining single-cell analysis with both loss- and gain-of-function studies of MCPyV infection, we demonstrated that the activity of ALTO leads to a decrease in MCPyV replication. Thus, we have identified ALTO as a crucial viral factor that modulates the STING-TBK1 pathway, creating a negative feedback loop that limits viral infection and maintains a delicate balance with the host immune system. Our study reveals a novel mechanism by which a tumorigenic virus-encoded protein can link Src function in cell proliferation to the activation of innate immune signaling, thereby controlling viral spread, and sustaining persistent infection. Our previous findings suggest that STING also functions as a tumor suppressor in MCPyV-driven oncogenesis. This research provides a foundation for investigating how disruptions in the finely tuned virus-host balance, maintained by STING, could alter the fate of MCPyV infection, potentially encouraging malignancy.

The causal relationship between immune cells mediating FIT3L, CCL4, OSM, and skin-derived deteriorated tumors.

OBJECTIVE: Observational studies have identified a dual effect of circulating inflammatory proteins and immune cells on cancer progression. However, the specific mechanisms of action have not been clarified in the exacerbation of cutaneous-origin tumors. Therefore, this study aims to investigate whether the causal relationship between circulating inflammatory factors and basal cell carcinoma (BCC), cutaneous malignant melanoma (SKCM), and cutaneous squamous cell carcinoma (cSCC) is regulated by immune cells. METHODS: This study employed the Two-Sample Mendelian Randomization (TSMR) approach to investigate the causal relationships between 91 circulating inflammatory factors and three prevalent types of skin cancer from a genetic perspective. Bayesian Weighted Mendelian Randomization (BWMR) was also used to validate correlation and reverse MR to assess inverse relationships. Subsequent sensitivity analyses were conducted to limit the impact of heterogeneity and pleiotropy. Finally, the two-step Mendelian Randomization (two-step MR) method was utilized to ascertain the mediating effects of specific immune cell traits in the causal pathways linking circulating inflammatory factors with BCC, SKCM, and cSCC. RESULTS: The Inverse Variance Weighted (IVW) method and the Bayesian Weighted Algorithm collectively identified nine inflammatory factors causally associated with BCC, SKCM, and cSCC. The results from Cochran's Q test, mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO), and MR-Egger intercept were not statistically significant (p < 0.05). Additionally, the proportions mediated by CD4+ CD8dim T cell %leukocyte, CD4-CD8-Natural Killer T %T cell, and CD20 on IgD-CD38-B cell for FIt3L, CCL4, and OSM were 9.26%, 8.96%, and 10.16%, respectively. CONCLUSION: Immune cell levels potentially play a role in the modulation process between circulating inflammatory proteins and cutaneous-origin exacerbated tumors. This finding offers a new perspective for the in-depth exploration of cutaneous malignancies.

TCF1-positive and TCF1-negative TRM CD8 T cell subsets and cDC1s orchestrate melanoma protection and immunotherapy response.

BACKGROUND: Melanoma, the most lethal form of skin cancer, has undergone a transformative treatment shift with the advent of checkpoint blockade immunotherapy (CBI). Understanding the intricate network of immune cells infiltrating the tumor and orchestrating the control of melanoma cells and the response to CBI is currently of utmost importance. There is evidence underscoring the significance of tissue-resident memory (TRM) CD8 T cells and classic dendritic cell type 1 (cDC1) in cancer protection. Transcriptomic studies also support the existence of a TCF7+ (encoding TCF1) T cell as the most important for immunotherapy response, although uncertainty exists about whether there is a TCF1+TRM T cell due to evidence indicating TCF1 downregulation for tissue residency activation. METHODS: We used multiplexed immunofluorescence and spectral flow cytometry to evaluate TRM CD8 T cells and cDC1 in two melanoma patient cohorts: one immunotherapy-naive and the other receiving immunotherapy. The first cohort was divided between patients free of disease or with metastasis 2 years postdiagnosis while the second between CBI responders and non-responders. RESULTS: Our study identifies two CD8+TRM subsets, TCF1+ and TCF1-, correlating with melanoma protection. TCF1+TRM cells show heightened expression of IFN-γ and Ki67 while TCF1- TRM cells exhibit increased expression of cytotoxic molecules. In metastatic patients, TRM subsets undergo a shift in marker expression, with the TCF1- subset displaying increased expression of exhaustion markers. We observed a close spatial correlation between cDC1s and TRMs, with TCF1+TRM/cDC1 pairs enriched in the stroma and TCF1- TRM/cDC1 pairs in tumor areas. Notably, these TCF1- TRMs express cytotoxic molecules and are associated with apoptotic melanoma cells. Both TCF1+ and TCF1- TRM subsets, alongside cDC1, prove relevant to CBI response. CONCLUSIONS: Our study supports the importance of TRM CD8 T cells and cDC1 in melanoma protection while also highlighting the existence of functionally distinctive TCF1+ and TCF1- TRM subsets, both crucial for melanoma control and CBI response.

SOCS1 and SOCS3 as key checkpoint molecules in the immune responses associated to skin inflammation and malignant transformation.

SOCS are a family of negative inhibitors of the molecular cascades induced by cytokines, growth factors and hormones. At molecular level, SOCS proteins inhibit the kinase activity of specific sets of receptor-associated Janus Activated Kinases (JAKs), thereby suppressing the propagation of intracellular signals. Of the eight known members, SOCS1 and SOCS3 inhibit activity of JAKs mainly induced by cytokines and can play key roles in regulation of inflammatory and immune responses. SOCS1 and SOCS3 are the most well-characterized SOCS members in skin inflammatory diseases, where their inhibitory activity on cytokine activated JAKs and consequent anti-inflammatory action has been widely investigated in epidermal keratinocytes. Structurally, SOCS1 and SOCS3 share the presence of a N-terminal domain containing a kinase inhibitory region (KIR) motif able to act as a pseudo-substrate for JAK and to inhibit its activity. During the last decades, the design and employment of SOCS1 and SOCS3-derived peptides mimicking KIR domains in experimental models of dermatoses definitively established a strong anti-inflammatory and ameliorative impact of JAK inhibition on skin inflammatory responses. Herein, we discuss the importance of the findings collected in the past on SOCS1 and SOCS3 function in the inflammatory responses associated to skin immune-mediated diseases and malignancies, for the development of the JAK inhibitor drugs. Among them, different JAK inhibitors have been introduced in the clinical practice for treatment of atopic dermatitis and psoriasis, and others are being investigated for skin diseases like alopecia areata and vitiligo.

Cancer cell plasticity defines response to immunotherapy in cutaneous squamous cell carcinoma.

Immune checkpoint blockade (ICB) approaches have changed the therapeutic landscape for many tumor types. However, half of cutaneous squamous cell carcinoma (cSCC) patients remain unresponsive or develop resistance. Here, we show that, during cSCC progression in male mice, cancer cells acquire epithelial/mesenchymal plasticity and change their immune checkpoint (IC) ligand profile according to their features, dictating the IC pathways involved in immune evasion. Epithelial cancer cells, through the PD-1/PD-L1 pathway, and mesenchymal cancer cells, through the CTLA-4/CD80 and TIGIT/CD155 pathways, differentially block antitumor immune responses and determine the response to ICB therapies. Accordingly, the anti-PD-L1/TIGIT combination is the most effective strategy for blocking the growth of cSCCs that contain both epithelial and mesenchymal cancer cells. The expression of E-cadherin/Vimentin/CD80/CD155 proteins in cSCC, HNSCC and melanoma patient samples predicts response to anti-PD-1/PD-L1 therapy. Collectively, our findings indicate that the selection of ICB therapies should take into account the epithelial/mesenchymal features of cancer cells.

Identification of novel disulfidptosis-related lncRNA signatures to predict the prognosis and immune microenvironment of skin cutaneous melanoma patients.

BACKGROUND: Skin cutaneous melanoma (SKCM) is an aggressive form of malignant melanoma with poor prognosis and high mortality rates. Disulfidptosis is a newly discovered cell death regulatory mechanism caused by the abnormal accumulation of disulfides. This unique pathway is guiding significant new research to understand cancer progression for targeted treatment. However, the correlation between disulfidptosis with long non-coding RNAs (lncRNAs) in SKCM remains unknown at present. METHODS: The Cancer Genome Atlas database furnished lncRNA expression data and clinical information for SKCM patients. Pearson correlation and Cox regression analyses identified disulfidptosis-related lncRNAs associated with SKCM prognosis. ROC curves and a nomogram validated the model. TME, immune infiltration, GSEA analysis, immune checkpoint gene expression profiling, and drug sensitivity were assessed in high and low-risk groups. Consistent clustering categorized SKCM patients for personalized clinical treatment guidance. RESULTS: A total of twelve disulfidptosis-related lncRNAs were identified for the development of prognosis prediction models. The area under the curve (AUC) values of the ROC curve and the nomogram provided reliable discrimination to evaluate the prognostic potential for SKCM patients. The TME played a crucial role in tumorigenesis, progression and prognosis, and the risk scores were closely related to immune cell infiltration. Meanwhile, the combination of chemotherapy, targeted therapy, and immunotherapy was recommended for low-risk patients based on drug sensitivity and immune efficacy analyses. CONCLUSION: We identified a risk model of twelve disulfidptosis-related lncRNAs that could be used to predict the prognosis of SKCM patients and help guide immunotherapy and chemotherapy for personalized treatment plans.

Real-world incidences and risk factors of immune-related adverse events in patients treated with immune checkpoint inhibitors: A nationwide retrospective cohort study.

Immune-related adverse events (irAEs) caused by immune checkpoint inhibitors (ICIs) are rare but fatal, requiring systemic steroid use. Therefore, to examine the outcomes, incidence, timing, and risk factors of ICI-associated steroid-requiring severe irAEs, we conducted a nationwide, retrospective, cohort study utilizing the Korean Health Insurance and Review Assessment database. We identified 357,010 patients with lung cancer, bladder cancer, or skin melanoma, eligible for ICI reimbursement in Korea between January 2012 to June 2020. Steroid-requiring severe irAEs following ICI treatment or treatment-emergent AEs following cytotoxic chemotherapy were defined as moderate- or high-dose steroid administration for over 2 consecutive days, along with corresponding ICD-10 codes indicating affected organ systems. The ICI-exposed group (N = 10,118) was compared to a matched cohort of 55,436 ICI-unexposed patients treated with cytotoxic chemotherapy. Incidences of acute severe irAEs requiring moderate- and high-dose steroids were higher in the ICI-exposed group (1.95% and 6.42%, respectively). The ICI-exposed group also had a higher risk of developing delayed severe irAEs requiring moderate- and high-dose steroid use (3.89% and 7.39%). Male sex, high comorbidity index, or previously diagnosed autoimmune diseases were associated with an increased risk of severe irAEs. Notably, 27.4-38.8% of the patients experienced recurrent severe irAEs after re-challenge with ICIs following moderate- or high-dose steroid use, with the severity matching the initial episode. Steroid-requiring severe irAEs were significantly more prevalent among patients exposed to ICIs than among those treated with chemotherapy in acute and delayed periods.

Developing Engineered Nano-Immunopotentiators for the Stimulation of Dendritic Cells and Inhibition and Prevention of Melanoma.

OBJECTIVE: This study aims to utilize PEGylated poly (lactic-co-glycolic acid) (PLGA) nanoparticles as a delivery system for simultaneous administration of the BRAFV600E peptide, a tumor-specific antigen, and imiquimod (IMQ). The objective is to stimulate dendritic cell (DC) maturation, activate macrophages, and facilitate antigen presentation in C57BL6 mice. METHODS: PEG-PLGA-IMQ-BRAFV600E nanoparticles were synthesized using a PLGA-PEG-PLGA tri-block copolymer, BRAFV600E, and IMQ. Characterization included size measurement and drug release profiling. Efficacy was assessed in inhibiting BPD6 melanoma cell growth and activating immature bone marrow DCs, T cells, macrophages, and splenocyte cells through MTT and ELISA assays. In vivo, therapeutic and immunogenic effects potential was evaluated, comparing it to IMQ + BRAFV600E and PLGA-IMQ-BRAFV600E nanoparticles in inhibiting subcutaneous BPD6 tumor growth. RESULTS: The results highlight the successful synthesis of PEG-PLGA-IMQ-BRAFV600E nanoparticles (203 ± 11.1 nm), releasing 73.4% and 63.2% of IMQ and BARFV600E, respectively, within the initial 48 h. In vitro, these nanoparticles demonstrated a 1.3-fold increase in potency against BPD6 cells, achieving ~ 2.8-fold enhanced cytotoxicity compared to PLGA-IMQ-BRAFV600E. Moreover, PEG-PLGA-IMQ-BRAFV600E exhibited a 1.3-fold increase in potency for enhancing IMQ cytotoxic effects and a 1.1- to ~ 2.4-fold increase in activating DCs, T cells, macrophages, and splenocyte cells compared to IMQ-BRAFV600E and PLGA-IMQ-BRAFV600E. In vivo, PEG-PLGA-IMQ-BRAFV600E displayed a 1.3- to 7.5-fold increase in potency for inhibiting subcutaneous BPD6 tumor growth compared to the other formulations. CONCLUSIONS: The findings suggest that PEG-PLGA nanoparticles effectively promote DC maturation, T cell activation, and potentially macrophage activation. The study highlights the promising role of this nanocomposite in vaccine development.

Tumor-Infiltrating T Cells in Skin Basal Cell Carcinomas and Squamous Cell Carcinomas: Global Th1 Preponderance with Th17 Enrichment-A Cross-Sectional Study.

Basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) are high-incidence, non-melanoma skin cancers (NMSCs). The success of immune-targeted therapies in advanced NMSCs led us to anticipate that NMSCs harbored significant populations of tumor-infiltrating lymphocytes with potential anti-tumor activity. The main aim of this study was to characterize T cells infiltrating NMSCs. Flow cytometry and immunohistochemistry were used to assess, respectively, the proportions and densities of T cell subpopulations in BCCs (n = 118), SCCs (n = 33), and normal skin (NS, n = 30). CD8+ T cells, CD4+ T cell subsets, namely, Th1, Th2, Th17, Th9, and regulatory T cells (Tregs), CD8+ and CD4+ memory T cells, and γδ T cells were compared between NMSCs and NS samples. Remarkably, both BCCs and SCCs featured a significantly higher Th1/Th2 ratio (~four-fold) and an enrichment for Th17 cells. NMSCs also showed a significant enrichment for IFN-γ-producing CD8+T cells, and a depletion of γδ T cells. Using immunohistochemistry, NMSCs featured denser T cell infiltrates (CD4+, CD8+, and Tregs) than NS. Overall, these data favor a Th1-predominant response in BCCs and SCCs, providing support for immune-based treatments in NMSCs. Th17-mediated inflammation may play a role in the progression of NMSCs and thus become a potential therapeutic target in NMSCs.

Developing a prognostic model for skin melanoma based on the persistent tumor mutation burden and determining IL17REL as a therapeutic target.

BACKGROUND: One popular and well-established marker for the immune checkpoint blockade (ICB) response is tumor mutation burden (TMB). Persistent TMB (pTMB), a subset of TMB, provides a better indicator to predict patient ICB therapy outcomes, as shown by some studies. Immune checkpoint drugs have significantly changed how melanoma is treated in recent years. METHODS: In this study, we integrated the TCGA-SKCM database and data of pTMB of TCGA from the paper that first mentioned pTMB and analyzed mutational and Immune characteristics associated with pTMB level in SKCM. Next, the predictive DEGs were identified the subgroups of pTMB by Cox regression and LASSO analyses to construct a pTMB-related signature. Finally, the expression and Biological functions of signature genes was detected, and further validated in vitro assay. RESULTS: In the current research, we explored the mutational and immunological features related to the level of TMB in cutaneous melanoma (CM). The high-pTMB subgroup exhibited an increasing incidence of gene changes and higher levels of immune cell infiltration. Subsequently, we established a pTMB-related signature based on the predictive DEGs and found the biological features and immune-associated variables between two distinct risk groups. Lastly, the results of the clinical sample validation demonstrated that the expression of IL17REL was down-regulated in the collected samples of individuals with CM. The in vitro assay results indicated that IL17REL effectively suppressed the proliferation, clonality, and migration of CM cells. CONCLUSION: In conclusion, we have developed a prediction model associated with TMB and subsequently validated the potential influence of IL17REL on Overall Survival (OS) in patients diagnosed with melanoma.

The Expression of Forkhead Box P3 T Regulatory Lymphocytes as a Prognostic Factor in Malignant Melanomas.

Since transcription factor Forkhead Box P3 (FoxP3) was identified as a specific regulatory T cell (Treg) marker, researchers have scrutinized its value as a potential novel therapeutic target or a prognostic factor in various types of cancer with inconsistent results. The present analysis was performed to assess the influence of Treg FoxP3 expression on the prognosis of primary melanoma and to evaluate the correlations with various clinicopathological prognostic factors. We analyzed all eligible patients with stage pT3 primary malignant melanomas treated in a tertiary cancer center. Immunohistochemical staining for Treg FoxP3 expression was performed on retrospectively identified paraffin blocks and subsequently correlated with the outcomes of the patients. A total of 81% of the patients presented a positive Treg FoxP3 expression, being correlated with a higher risk of lymph node metastasis, tumor relapse, and death. Moreover, positive expression was statistically associated with a shorter OS. The tumor relapse rate was estimated at 36.7%. A positive expression of Treg FoxP3 and lymph node metastasis were associated with a higher risk of death based on multivariate analysis. Treg FoxP3 expression may be used as an independent prognostic factor in patients with malignant melanoma to evaluate tumor progression and survival.

Noninvasive Transdermal Administration of mRNA Vaccines Encoding Multivalent Neoantigens Effectively Inhibits Melanoma Growth.

It is difficult to obtain specific tumor antigens, which is one of the main obstacles in the development of tumor vaccines. The vaccines containing multivalent antigens are thought to be more effective in antitumor therapy. In this study, a mRNA encoding three neoantigens of melanoma were prepared and encapsulated into the mannosylated chitosan-modified ethosomes (EthsMC) to obtain a multivalent mRNA vaccine (MmRV) for transcutaneous immunization (TCI). MmRV can effectively induce maturation of dendritic cells, with a better performance than mRNA of a single neoantigen. TCI patches (TCIPs) loading MmRV or siRNA against PDL1 (siPDL1) were prepared and applied to the skin of melanoma-bearing mice. The results showed that TCIPs significantly increase the levels of TNF-α, IFN-γ, and IL-12 in both plasma and tumor tissues, inhibit tumor growth, as well as promote infiltration of CD4+ and CD8+ T cells in the tumor tissues. Furthermore, the combination of MmRV and siPDL1 showed much better antitumor effects than either monotherapy, suggesting a synergistic effect between the vaccine and PDL1 blocker. In addition, the treatment with the TCIPs did not cause damage to the skin, blood, and vital organs of the mice, showing good biosafety. To the best of our knowledge, this work is the first to construct a noninvasive TCI system containing MmRV and siPDL1, providing a convenient and promising approach for tumor treatment.

Prognosis and immunotherapy in melanoma based on selenoprotein k-related signature.

Selenium and selenoproteins are closely related to melanoma progression. However, it is unclear how SELENOK affects lipid metabolism, endoplasmic reticulum stress (ERS), immune cell infiltration, survival, and prognosis in melanoma patients. Transcriptome data from melanoma patients was used to investigate SELENOK levels and their effect on prognosis, followed by an investigation of SELENOK's effects on immune cell infiltration. Furthermore, a risk model based on ERS, lipid metabolism, and immune-related genes was constructed, and its utility in melanoma prognosis was evaluated. Finally, the drug sensitivity of the risk model was analyzed to provide a reference for melanoma therapy. The results showed that melanoma with a high SELENOK level had a greater degree of immune cell infiltration and a better prognosis. Additionally, SELENOK was found to regulate ERS, lipid metabolism, and immune cell infiltration in melanoma. The risk model based on SELENOK signature genes successfully predicted the prognosis of melanoma, and the low-risk group exhibited a favorable immunological microenvironment. Furthermore, high-risk patients with melanoma were candidates for chemotherapy with RAS pathway inhibitors, whereas low-risk patients were more susceptible to routinely used chemotherapy medicines. In summary, SELENOK was shown to regulate ERS, lipid metabolism, and immune cell infiltration in melanoma, and SELENOK was positively associated with the prognosis of melanoma. The risk model based on SELENOK signature genes was valuable for melanoma prognosis and therapy.

Transcriptional switches in melanoma T Cells: Facilitating polarizing into regulatory T cells.

Melanoma is a malignant skin tumor with a high mortality rate. Regulatory T cells (Tregs) are immune cells with immunosuppressive roles, however, the precise mechanisms governing Treg involvement in melanoma remain enigmatic. Experimental findings unveiled different transcription factor switches between normal and tumor T cell, with heightened FOXP3 and BATF in the latter. These factors induced immunosuppressive molecules and Treg maintenance genes, polarizing tumor T cells into Tregs. Spatial transcriptomics illuminated the preferential settlement of Tregs at the melanoma periphery. Within this context, FOXP3 in Tregs facilitated direct enhancement of specific ligand gene expression, fostering communication with neighboring cells. Novel functional molecules bound to FOXP3 or BATF in Tregs, such as SPOCK2, SH2D2A, and ligand molecules ITGB2, LTA, CLEC2C, CLEC2D, were discovered, which had not been previously reported in melanoma Treg studies. Furthermore, we validated our findings in a large number of clinical samples and identified the Melanoma Treg-Specific Regulatory Tag Set (Mel TregS). ELISA analysis showed that the protein levels of Mel TregS in melanoma Tregs were higher than in normal Tregs. We then utilized SERS technology to measure the signal values of Mel TregS in exosome, and successfully discriminated between healthy individuals and melanoma patients, as well as early and late-stage patients. This approach significantly enhanced detection sensitivity. In sum, our research elucidated fresh insights into the mechanisms governing Treg self-maintenance and communication with surrounding cells in melanoma. We also introduced an innovative method for clinical disease monitoring through SERS technology.

Corticosteroids and other immunosuppressants for immune-related adverse events and checkpoint inhibitor effectiveness in melanoma.

BACKGROUND: Recent studies indicate an association between immunosuppression for immune-related adverse events (irAEs) and impaired survival in patients who received immune checkpoint inhibitors. Whether this is related to corticosteroids or second-line immunosuppressants is unknown. In the largest cohort thus far, we assessed the association of immunosuppressant type and dose with survival in melanoma patients with irAEs. METHODS: Patients with advanced melanoma who received immunosuppressants for irAEs induced by first-line anti-PD-1 ± anti-CTLA-4 were included from 18 hospitals worldwide. Associations of cumulative and peak dose corticosteroids and use of second-line immunosuppression with survival from start of immunosuppression were assessed using multivariable Cox proportional hazard regression. RESULTS: Among 606 patients, 404 had anti-PD-1 + anti-CTLA-4-related irAEs and 202 had anti-PD-1-related irAEs. 425 patients (70 %) received corticosteroids only; 181 patients (30 %) additionally received second-line immunosuppressants. Median PFS and OS from starting immunosuppression were 4.5 (95 %CI 3.4-8.1) and 31 (95 %CI 15-not reached) months in patients who received second-line immunosuppressants, and 11 (95 %CI 9.4-14) and 55 (95 %CI 41-not reached) months in patients who did not. High corticosteroid peak dose was associated with worse PFS and OS (HRadj 1.14; 95 %CI 1.01-1.29; HRadj 1.29; 95 %CI 1.12-1.49 for 80vs40mg), while cumulative dose was not. Second-line immunosuppression was associated with worse PFS (HRadj 1.32; 95 %CI 1.02-1.72) and OS (HRadj 1.34; 95 %CI 0.99-1.82) compared with corticosteroids alone. CONCLUSIONS: High corticosteroid peak dose and second-line immunosuppressants to treat irAEs are both associated with impaired survival. While immunosuppression is indispensable for treatment of severe irAEs, clinicians should weigh possible detrimental effects on survival against potential disadvantages of undertreatment.

Phase I/II clinical trial of brentuximab vedotin for pretreated Japanese patients with CD30-positive cutaneous T-cell lymphoma.

Brentuximab vedotin (BV), a conjugate of anti-CD30 antibody and monomethyl auristatin E, has emerged as a promising treatment option for refractory CD30+ mycosis fungoides (MF) and primary cutaneous anaplastic large-cell lymphoma (pcALCL). BV has been shown to be safe and effective in treating Hodgkin's lymphoma and peripheral T-cell lymphoma. This multicenter, prospective, single-arm phase I/II study evaluated the efficacy of BV in Japanese patients with CD30+ cutaneous lymphomas, namely CD30+ cutaneous T-cell lymphoma. Participants were divided into two groups: those with CD30+ MF or pcALCL (cohort 1, n = 13) and those with CD30+ lymphoproliferative disorders other than those in cohort 1 (cohort 2, n = 3). The studied population included the full analysis set (FAS), modified FAS (mFAS), and safety analysis set (SAF). These sets were identified in cohorts 1 and 1 + 2 and labeled FAS1 and FAS2, mFAS1 and mFAS2, and SAF1 and SAF2, respectively. Each treatment cycle lasted 3 weeks, and BV was continued for up to 16 cycles after the third cycle based on treatment response. The primary endpoint was the 4-month objective response rate (ORR4) determined by the Independent Review Forum (IRF). ORR4 was 69.2% for FAS1 and 62.5% for FAS2 (P < 0.0001). Secondary endpoints of ORR, assessed using the global response score (53.8% in FAS1) and modified severity-weighted assessment tool (62.5% in FAS1), using the IRF, provided results comparable to the primary findings. The incidence of ≥grade 3 adverse events (≥15%) in SAF1 was peripheral neuropathy in three patients (23%) and fever and eosinophilia in two patients (15%). In conclusion, BV showed favorable efficacy, tolerability, and safety profile in Japanese patients with relapsed or refractory CD30+ primary cutaneous T-cell lymphoma. The trial was registered with University Hospital Medical Information Network Clinical Trials Registry, Japan (protocol ID: UMIN000034205).

Comprehensive analysis of single cell and bulk RNA sequencing reveals the heterogeneity of melanoma tumor microenvironment and predicts the response of immunotherapy.

BACKGROUND: Tumor microenvironment (TME) heterogeneity is an important factor affecting the treatment response of immune checkpoint inhibitors (ICI). However, the TME heterogeneity of melanoma is still widely characterized. METHODS: We downloaded the single-cell sequencing data sets of two melanoma patients from the GEO database, and used the "Scissor" algorithm and the "BayesPrism" algorithm to comprehensively analyze the characteristics of microenvironment cells based on single-cell and bulk RNA-seq data. The prediction model of immunotherapy response was constructed by machine learning and verified in three cohorts of GEO database. RESULTS: We identified seven cell types. In the Scissor+ subtype cell population, the top three were T cells, B cells and melanoma cells. In the Scissor- subtype, there are more macrophages. By quantifying the characteristics of TME, significant differences in B cells between responders and non-responders were observed. The higher the proportion of B cells, the better the prognosis. At the same time, macrophages in the non-responsive group increased significantly. Finally, nine gene features for predicting ICI response were constructed, and their predictive performance was superior in three external validation groups. CONCLUSION: Our study revealed the heterogeneity of melanoma TME and found a new predictive biomarker, which provided theoretical support and new insights for precise immunotherapy of melanoma patients.

Vaccimel immunization is associated with enhanced response to treatment with anti-PD-1 monoclonal antibodies in cutaneous melanoma patients - a case reports study.

Cancer vaccines are gaining ground as immunotherapy options. We have previously demonstrated in cutaneous melanoma (CM) patients that adjuvant treatment with VACCIMEL, a mixture of four irradiated CM cell lines co-adjuvanted with BCG and GM-CSF, increases the cellular immune response to melanocyte differentiation antigens, cancer-testis antigens and neoantigens, with respect to basal levels. On the other hand, it is also known that treatment with anti-PD-1 monoclonal antibodies (MAbs), acting on pre-existing tumor-reactive lymphocytes, induces clinical responses in CM patients, albeit in a fraction of treated patients. A combination of both treatments would appear therefore desirable. In this paper, we describe CM patients who, having progressed even years after vaccination, were treated with anti-PD-1 MAbs. In 5/5 of such progressor patients, complete responses were obtained which lasted between 3 and 65+ months. Three of the patients remain disease-free and two recurred. One of the patients passed away after a recurrence of brain metastases. We suggest that clonally expanded reactive lymphocytes induced by VACCIMEL partially remain as memory cells, which may be recalled after tumor recurrence and may foster ulterior activity of anti-PD-1 MAbs.